Closure operating mechanism



Oct. 3, 1933. J. E. BANCROFT cLosURE OPERATING MECHANISM 3 Sheets-Sheet 2 Filed March 14, 1928 NVENTOR @/JMES E. BANCROFT WVVNESS 1541 UCL 3, J, E. BANCROFT CLOSURE OPERATING MECHANI SM Filed March 14, 1928 3 Sheets-Sheet 3 INVENTOR w PVN Ess {f4/15S E. BANCROFT Q. fi BYQQNVN Lgf/Lg ATTORN EY l to Patented Oor. 3,219313 n n, "izsir d y cLosURs oPyEnA'rrNG MECHANISM v f ramona: nanofoft, notion, Miou., ossignor, by'.

mesne assignments, to'The Peelle Company, New York, N. Y., a corporation of New York i', Applicationinarohl y14, 19,28.` lsori'aiNo. 261,572"

" f tciaims. (o1. 268-59) yThis invention-relates to closure operating mechanism and more particularly yto ,a` power driven apparatus arranged to open and closea V vme'chanisrnfor the motor; n, .y

Fig. '7* is a detail showing the `construction of p50 f door.

" '"5 sliding doors arek oftenfuseoiin oonneotionwth freight elevatorshafts, and vthese doors have to be opened andclosed a' great many times during the course of aday.` It is important that the door `ateach iioor move as rapidly as' possible so .as'fto the elevator, and that the door start and stop easily and graduallyfto avoid undesirable noise `and an extraordinary amount ofk expense for maintenance.

f standard equipment i maybe utilized tor, varirous'sizesand types of doors and motors andin all sorts of locations.r A 'further desirable lfeature Y .involves'the/ use of a motorwhich may run 20 through-a given travel cycle'and automatically limit itspwn operationinsuch a manneras to stop when the door is in a fully open or a fully closedgposition; vrand adjustments should be provided which permit the final positions of the door apparent to one skilled in the art; my inventionV resides in the combination Of parts set `forth in l the speciiication and covered by the claimsap- 4D `pendedhereto.

f `loodiment of my Vinvention f and 7in whichy like reference numeralsindicatelike parts g f! Fig-,1'` is an elevation of myrapparatus consfnected. to a pair-otL vertically slidable counterbalanced. doors, the doorsybeingshoWninthe clearnessioffillustration; y 1 .u

Fig. 2 isv applan view gof the parts shown in (Fig. Bisa plan view similar gtoy k1ig`.\2,butwith the parts? inthe position they ,will assume ,when the doorsare openy, i i ff r `r`Fig. 4f is an enlarged perspective ,view ofxone end ofthe .sliding'ban f f .f

` f `closed position, andparts being-broken awayior avoid any unnecessarydelay in the operationof p i rWhile the invention yis applicable to a single It` is also de'sirablefthat the 1,5, mechanism be readily `adjustable r4so` that a sideof the Wall. rBy this means each door serves `as kla counterweightfor the other, and thefonlyw `resistance vto be overcome in operating the doors is that due to inertia and friction; Doors` of ythis to be changed withootaseouhg the p automatic A Referring tothe drawings illustrating one ein-` y.25for these,outersprocketsf In.order:torerduce` v the ycost and simplify the constructiony the` intern l mediate y, portion ofA 'the chain, which 'does` not i* `22and 23 Will both turn inqthe sarney}direction, Vtheordinary construction isthat shown in the `drawings in which itis apparent that sprockets I 22 and123jturn in oppositedirections. With this Fig; 5 yis an enlarged perspective View ofene Aof the `guide bearings forthe sliding bar;

Fig.` 6 is an `enlarged 'elevation of the braking the limit switch, together with a diag'ranroiv the "electric wiring connections thereto; and- Fig. Sis a perspective View of the Worm: gear `reduction unit and limit switch with parts broken away for clearnes's of illustration. 65

door, and to doors of various types, I have illustrated one` embodimentfas appliedto a pair of vertically slidable 'counterebalanced doors of the type frequently used injconnection with freight .elevator shafts. The `upperdoor 10 and the lower door 11 may be arranged to slide vertically in suitable guides, not shown, behind a rectangular openingxl in a verticalfwall 14. This Wall may form a portion of an elevator shaft or hatchway.

sprocket ywheels 17 rotatably mounted ontherintype are frequently operated `by hand,it being merely/necessary tofgrasp one door and move 'it to the desired position,` thereby causing the other door to move also. 'g However, suchdoors `are ordinarily of very 4heavy construction and operation' by hand is undesirably 4slow andlaborious. 0 In order to operate the doors by power pro- Vide suitable connections, such as shafts 19 and 20, Whichare keyed to the .sprockets 17 and ex-` i tendpentirely through thewall 14 to the outside thereof. Various methods ofzdrivingthese*shafts may be utilized Within thefscope of'iny invention,y

- but I'preierlto mount sprockets 22 and 23Y on their outer ends, and t0 pvlovideasuitablechain `pass over the sprockets during operation, may v be replaced by a rigidsrod` 26. While itfis possible to so mount the doorsfthat the `sprockets `los arrangement it is necessary for the chain 25jto pass'around the sprocket 22 rin one directionk and `1`1v0 f around sprocket 23 in the other direction, as shownclearly in Fig. 1.

The doors 10 and 11 are operated by asuit-` able source of power, such as electric motor 30, which may be conveniently mounted upon a base 31 attached to the wall 14', above the openingl 13. While this motor maybe of any suitable type, Iy prefer to use a motor which is' easily reversible, and I have found a three phase induction motor satisfactory when the proper electric current is available.

In order to reduce the load upon the driving motor and to avoid allshock and slamming of the doors during operation, I so connect the motor to the chain 25 as to give it, as well as the doors connected thereto, a vsubstantially simple harmonic motion. As iswell known, a simple harmonic motion is the motion of the projection on a straight line of a point moving at a uniform velocity in a circular path. While various mechanical devices may be utilized for this connection, I prefer to arrange a crank which will be ony its dead center position when vthe door is either fully open or fully closed. While a crank, dueto so-calledv angularity, does not give a theoretically exact simple harmonic motion, nevertheless, it is sufficiently -near to the theoretical connected to the motor.

for all practical purposes. and it has various advantages over other constructions.` As illustrated, I provide a crank 33 which 'is rotatable `about a vertical axis, although it isapparent it may be arranged for rotation about a horizontal axis if it is desired. The crank 33 is arranged to be rrotated by the motor 30 through a suitable speed reduction device, and for this purpose I mount the crank on thes'haft34v (Fig. 8) of a 'worm gear which is driven by a worm 37 directly The worm and worm gear are preferably enclosed in a suitable casing l 38, mounted upon-the bracket 31.

In order to form a suitable connection between the crank 33 andthe chain 25, I provide a bar 40, shown substantially :square in cross section, which is arranged to slide inI a pair of guides 41 mounted upon the wall 14. Each guide 41,

.as shown in Fig. 5, is, provided with a slot 42 of the proper size and shape to fit the bar 40. Each end of the bar is connected. to one end of the .chain 25, and for this purpose one end of the' bar is provided with a downwardly projecting portion 44, illustrated in detail Fig. 4. This projection44 has an Vopening 45 therethrough of sufiicient size to permit theY chain 25 andthe rodf26 to ,pass freely therethrough. The motion of the crankx33 is transmitted to the bar 40 4by means of a connecting rod 47 which is pivoted to the crank at 48 and to the bar at 49. As shown in Figs. 2 and 3 the parts areso constructed andrarranged that the crank 33 is on deadcenteigthat is, in line lwith 'the connecting rod, whenthe doors are fully open ory ,fully closed.y l

While'theratio betweenv the different sprock- 'ets may be varied to accommodate the door op- 'erating mechanism to doors having different V"amounts of travel, I prefer to provide means for length of the crank may be varied by sliding the extension 51 relative to the arm 52 and clamping it in its new position by means of the screws 54.

Various electrical devices and connections may be utilized within the scope of my invention for controlling .the electric motor to open and close the doors. I havev illustrated diagrammatically in Fig. 7 one simple arrangement of apparatus for this purpose. As shown, the motor 30 is connected to a suitable source of three phase alterhating current through a magnetically operated reversing switch 61 having magnet coils 62 and 63. This switch 61, which is of a type well-known in the art, is so arranged that when coil 62 is energized the switch will be thrown so as to operate the motor 30 in one direction and when the coil 63 is energized it will be thrown to operate the motor in the opposite direction. When neither coil is energized the switch will be open and the motor circuitbroken. Push buttons 65 and 66 are provided for opening and closing the doors respectively. A suitable limit switch 68 is provided for the purpose of auto- 1 The limit switch 68 comprises a central stationary vcontact member 69 withl movable contact members. 7l and 72 at each side thereof. Contacts 71 and 72 are mounted upon pivoted arms 74 and 75 respectively. Springs 77 and 78 tend to hold con- ;tacts 71 and 72 vagainst thev central contact 69. The central contact member 69 is connected by a suitable electric conductor with one voi" the main; power wires and the movable Acontacts 71 and 72 are connected with another of the main power wires through coil 63 and push button 66 and coil. 62 and push button65 respectively.

As shown in Fig. 8, the limit switch 68 may be mounted adjacent to' the worm gear casing 38 and arranged to be operated by the movement of the crank 33. For this purpose an arm 901s pivotally attached to the casing 38 by means of a vertical' stud 91. This arm 90 has at its outer end an .enlarged portion 93 located between the arms 74 and 75. At its inner end the arm 90 carries a pivotally mounted cam roller 94. Suitable cam members 96 and 97 are adjustably mounted by meansof screws 98 on a horizontal disk 100 integral with the crank 33. These parts are so arranged that as the doors approach either one of their extreme positions one of the cam members 96 and 97 will contact with the roller and move the arm 90 about the stud 91, thereby causing one of the contact members 71 and 72 to be moved away `from the central contact 69. In order to insure the stopping of the motorBO as soon as the current supplied thereto is interrupted, I prefer to provide the'braking device illustrated in Fig. `6. This comprises a pair of brake shoes 106 mounted upon vertical arms 107 whichl are pivoted at their lower ends. A tension spring 109 connects the arms at their upperends and normally holds the brake shoes inncontact with ay pulley 110 mounted upon the motor shaft. In order to hold the shoes 106 out of contact with the pulley during the period when the motor is supplied with electric power, I provide an'electro-magnetic coil 115 which is connected across two of the motor terminals.

.This coil 115 is arranged when energized toV attract an armature 116 mounted upon the pivoted lever 118. The lever 118 is connected by a vertical link 119 vwith the toggle arms 121 `which are pivoted to the upper" ends of thefarms 107.

1,928,611; i Y .3f-A

\ 2r Aclosure operatingmechanism foraslidablel` It is apparent that when the armature 116 is attracted by the coil 115 it will result in forcing the upper ends of the arms 107 apart/against the actionof the spring 109 and thereby remove the brake shoes from the pulley y110 and permitk the motor to rotate freely. AAs soon as the motor current is interrupted the coil L115will be deenergized and the spring 109 will pull the shoes 106-into 'contact with the pulley 110 and bring the motor'to an immediate stop. ySince the'velocity of the doorswhen they reach leither ex` treme 'position is zero,as a result of the` simple y'brake must stop the doors in addition to theA harmonic motion, the brake has only the momentum of the motor armature to overcome. Hence a relatively small brake can be used, as compared with prior constructions in which the motor. k v

The operation of my apparatus will nowk be apparent from the above disclosure. Suppose the doors are originally in the closed position, yas

` shown in Fig. 1. To open them it is merely `necessary to press the push button 65. `This will permit the currentto flow throughvthe coil 62, con

tact 72, and contact 69. This will throwthe magvnetic switch 61 so as to `operate the motor 30 and j rotate the crank 33 inthe direction of the arodoor comprisingv adriving wheel, a flexible power.

transmission connection between said wheel and row in Fig. 2.. Since the crank arm 33 isforigiinally on dead center it is apparent that avery small starting torque will be required ofthe motor As 'the crank 33 rotates they doors will gradually reach a high rate of speed and then gradually'slow down to a smooth stop without any shock or slamming.L As the doors approach their fully` open position the cam 97 will contact with the roller 94and cause the armk 90 to swing'about its pivot andthereby lift the contact member`72 away from the contact 69. This breaks the circuit through thecoil 62 and the magnetic switch'l will vthen return to neutral position and break the 'main motor circuit, thereby stopping themotor.l To close the doors, it is merely necessaryto operatev the push button 66 whereupon current ywill flow through the coil 63 and the contacts .71' and 69 soas to throw the switch 61 and cause the motor to operate and rotate the crank 33 in thejdirection of thearrow in Fig. 3. As the kdoors approachtheir fully closed position the cam `96 -will strikethe cam roller 94, thereby swinging the arm 9,0k and lifting contact '71 awayfrom contact,k 69, `thus stopping the door. With my apparatus it is pos sible to use a motor of a small size and yet operate the doors lvery rapidlyy without overloading the motor or causing any shock or damagetothe doors. The apparatus is easily installedf'quiet in operation ,and requires a minimum of attention.

Having thus described my invention,` whatfI claim as new and desire' to secure by Letters `Patent is:-.

1. A closure operating mechanism for aslidable door to operate the same, adrivingmotor, and

connections between said motor and wheelar'4r Y ranged to give the door a` substantially ysimple harmonic motion as it moves from one extreme position to the other.

door comprising a driving wheel, a flexible power o transmission member passing over said wheel and driven thereby, connections between said memberand the door, an electric motor, a crank arm driven by said motor, and means connecting the crank arm to the wheel to rotate the latter in either direction and thereby operate the door.

3. A closure operating mechanism for a slidable door comprising a driving wheel, a iiexible power transmission member drivenby said'wheel and connected to move the door to an open or av closedposition, a driving chain connected with ysaid wheel, a motor, a crank connection between the motor and the driving chain, and means for limiting the extent of travel of the door in either direction. i

soy

4... An operating mechanism for a slidable door comprising a driving wheel, a flexible power transmission connection between said wheel `and door to open and close the same, a driving motor, a crank driven` thereby, and connections including a connecting rod between said crank and wheel vto rotate the same, said parts being so constructed and arranged that the crank will start and stop substantially on adead jcenter lwhen the door is the open `and closed position.

5. vA closure comprising aslidable door, a driving Wheel, a exible power transmission member connecting said wheel with the door,` a shaft connected to: said driving wheel` a sprocket wheel mounted on the shaft. a. chain passing over the sprocket wheel, a slidable bar connected to the chain, a motor driven crank, and a connecting rod pivoted at one end to the crank and at the other` 11(7)4 A end tothe slidable bar;

6. A closure comprising a'vertically slidable door, a rotatable driving `wheel at eachend of the door, a iexible power transmission member passing over each `wheel and connectedfto thef doorin such a manner that rotation of the two n wheels in opposite directions will slide the door in one direction, a shaft connected to each wheel,

a sprocket mountedjoneach shaft, a chain 'which passes around one sprocket in one direction and the other sprocket" in the other direction, a slidaf ble bar connected to each end of said chain, and i a. power operated mechanism connected to slide said bar.

'7. A closure comprising `a slidable door 'ar- 125 rangedto move to an open ,or closed position, an

electric motor, a crank arm driven by the motor, a connecting rod driven by the crank arm and arranged to slide the door,y said parts being so constructed and arranged that the crank arm will be substantiallyon one dead center when o the door is in a fully open position and substantially on' the other dead center when the door is in a fully closed position, means including a limit i switch arranged to interrupt theelectric' current 135k supply to the motor when the` door reaches such' open or closed position, and an electro-magnetic interruption of said current supply.

JAMES E. BANCROF'I".

lbrakearranged to stop rotation of the motor upon 

